Various 2-arylisoxazolin-3-one derivatives and synthesis methods thereof are described in Heterocycles, 20(6), pages 1123-1126 (1983), Chemical and Pharmaceutical Bulletin, 30(9), pages 3097-3105, Heterocycles, 19(3), pages 515-520, Heterocycles, 19(3), pages 521-524, Journal of Heterocyclic Chemistry, 17(4), pages 727-731, Chemical and Pharmaceutical Bulletin, 19(7), pages 1389-1394, Japanese Patent Application (OPI) No. 104274/80 (the term "OPI" as used herein means an "unexamined published application"), etc.
However, 2-arylisoxazolin-3-one derivatives wherein the substituent at the 2-position of the isoxazoline nucleus is an aryl group substituted by an electron attractive group(s) having a higher electron attractive property than a chlorine group have never been known and also such derivatives having a halomethyl group at the 4-position of the isoxazoline nucleus have never been known.